Packing



April 26 1927.

.PACKING Filed Novi 14; 1-921 A. EKMAN fnvenor oqfforlze'yg PatentedApr. Z6, 1927.

Unir-ED ist-Aries jfla-A*rlrrr "Fries ANDREW DKMAN, or en /inn RAPIDS,ivrrcrrroAN, l AssreNon, `Br ransnn AssreN- MENTS, 'ro'tnnrcx SYNDICATE,eoiurosnn or vfrDLiAMD. jen-apron AND D. njcoN- Non, Borri or NEWARK,NEW JERSEY, AND r. J. Pannen AND JIJ. HARRIS, :corn

OF MONTCLAIR, NEW JERSEY.

PACKING.

Application led November 14, 1921.

My invention relates to an improved pack ing device adapted"particularly, but not exclusively, for dash pots tor use in addingmachines and like mechanisms and thro-ugh which fluid, such as oil, isforced from one l:,ide of a piston to the other by the relative movementbetween the piston and the coacting pot or casing. The principal objectoit the invention is to obviate objectionable leakage from the dash potof the oil or other rctarding liquid.

1n order that my invention may be better understood, attention isdirected to the accompanying drawing roi-ming a part ot thisspecification and illustrating a dash pot containing one embodiment ofmy invention.

ln the drawing the ligure is a View ot the dash pot partly inlongitudinal cross section and partly in elevation.

Referring to the drawing, the cylindrical pot or casing 1 has mountedtherein the piston 2 which is formed With a piston rod 3 extendingthrough the cap t which provides one endL Wall ot the casing. 1n orderto permit the oil in the casing to pass from one side ot the piston tothe other upon the relative movement between the piston and the casing,there is provided a passage 5 passing axially through the piston rod andpiston and a port or opening 6 extending transversely through the pistonrod into the passage The flow of retarding liquid through the port 6,and accordingly also the speed ot operation olf the dash pot, iscontrolled, as shown, by a rod 7 fitting Within the piston rod andhaving one end arranged to close more or less of the port 6. The rod 7,as shown, is threaded into the piston rod, as shown at 8, to permitadjustment thereof for varying the amount of opening of the port 6. Tofacilitate adjustment of the rod 7 the piston rod 3 is provided With aWing nut 10 which is lined against rotation with respect to the pistonrod in any suitable manner, as by the provision of flat surfaces betweenthe piston rod and Wing nut. The piston rod and the port rod 7 may beclamped in adjusted relation to each other by the lock nut 11.

The objectionable leakage ot oil or other retarding fluid from the dashpot usually Serial No. 514,884.

occurs at the joint between the piston rod and the casing. My inventioncomprises means for making the dash pot fluid tight at this point. Thesemeans, as shown, comprise a packing member la which is preferably formedof thin sheet material, such as steel, copper or other suitablematerial. The thickness of the sheet depends upon the ma terial employedand upon the type oi' dash pot in which it is to be used. n a dash poti'or use in an ordinary adding machineI a sheet of soft brass having athickness between eight and twelve one thousandths of an inch issuitable. The member 1a is clamped, so as to form a tluid tight joint atits outer edge between the body of the dash pot and the cap 2, thelatter being threaded upon the body of the dash pot. The central portionot the member V1li is in the lorm ot' a sleeve 15, the inner portion ofWhich is tapered towards and into engagement With the piston rod. Afollower ring 16 slidable along piston rod 3 has a tapered inner sur-'lace portion 17 which engages the tapered portion of the sleeve and isadapted, b y reason of the pressure exerted upon the tolloiver 16 by thespring 18, to Wedge the tapered portion ot' the sleeve 15 tightlyagainst the surface of the piston rod so as to form a fluid tight joint.rlihis spring, as shown, is concentric with the piston rod and has oneend in engagement with the piston and the other in engagement With ashoulder 19 formed on the follower 16. Vith this arrangement of thespring the pressure ot the spring increases during the stroke ot thepiston when the pressure of the fluid at the joint between the pistonrod and casing is greatest; so that the packing is forced most firmly inplace When the tendency to leak is greatest.

It is to be understood that my invention is not limited to dash pots andthat many modifications may be made Without departing from the spirit ofmy invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent of the United States is In a device of the characterdescribed, the combination with a casing having a` piston movabletherein and a piston rod passing through one end thereof, of a, sheet ofmetallio packing having its outer edge secured to said casing and havinga sleeve portion littiug around said piston rod, e 'ollowei` on saidpiston rod having a wedge action on said sleeve and a spring one end ofwhich is in engagement with said follower and the other end of which isin engagement with said piston whereby the pressure of said followei` onsaid sleeve is varied according to the movement of said piston.

In testimony whereof, I have Signed my name to this specification.

ANDREW EKMAN.

